Stop collar for well casing



Aug. 5, 1958 J. w. E. HANES STOP COLLAR FOR WELL CASING 3 Sheets-Sheet 1Filed March 19, 1954 INVENTOR: (IQ/145$ EmvEs,

Arroe/vsys.

J. w; E. HANES 2,846,016

STOP COLLAR FOR WELL CASING Aug. 5, 1958 4 3 Sheets-Sheet 2 Filed March19, 1954 INVENTOR.

0 2M455 WE. HANES,

ATTORNEYS.

1958 J. w. E. HANES 2,846,016

STOP COLLAR FOR WELL CASING Filed March 19, 1954 5 Sheets-Shegt 3 JAMESWE. HAM/E5,

ZZoWM [4' 14 T TOENEYS.

as to hold the strip or band in constricted condition.

STOP COLLAR FOR WELL CASING James W, E. Hanes, Ventura, Califi,assignor, by mesne assignments, to Huntsinger Associates, a jointventure Application March 19, 1954, Serial No. 417,290

2 Claims. (Cl. 28752.04)

This invention relates to equipment for oil well casings, or the like,and particularly to a novel collar construction for limiting movement ofcasing guiding structures, or the like, or for securing other structuresto the exterior of the casing.

In deep well operations, casings of high tensile strength are required.For this purpose, casings made of heattreated steel are commonlyprovided. Structures such as casing centralizers are carried formovement on the easing bythe aid of stop collars or rings afiixed on theeasing. It has been common to weld metal collars in place on the casingfor this purpose. Unless very carefully performed, the welding processdetrimentally alters the grain structure of the steel casing, resultingin a loss of strength. Furthermore, the welding process alters theuniformity of the grain structure, resulting in localized stresses andcracking.

It is an object of this invention to overcome these difficulties and toensure against any adverse alteration of the metallurgical properties ofhigh quality casing material. For this purpose, a metal strap or band isconstricted about the casing for frictional coupling thereto, a yieldingmember made of rubber or suitable plastic material being interposedbetween the band and the casing to provide a firm frictional grip. Inone form of the invention, no-vel separable clamp elements mounted onthe ends of the band or strip serve to constrict the band or strip aswell In other forms of the invention, the band or strip has elementsthat may be interconnected to hold the band or strip in constrictedcondition, a novel tool constricting the band or strip to bring theelements into engagement.

It is another object of this invention to make it possible to locatecollars, or the like, on the exterior of substantially cylindricalcasing structures without altering the structure of the casing per se.It is still another object of this invention to obviate welding ofcollars, or the like, to the exterior of the casing.

It is yet another object of this invention to provide a simple collarconstruction or the like that'can be quickly secured to the exterior ofa casing by simple operations.

It is another object of this invention to providean improved clampstructure particularly that makes it possible to maintain the size ofthe collar in sustaining the stresses occasioned by the clamping forces.i

It is another object of this invention to provide a. device ottbischaracter that conveniently maybe made ans-integral part of thestructure intended to becarriedby the casing. i

It is another object of this invention to provide a novel tool forconstricting a band about a casing and bringing simple elements at theends of the band into engaging relationship. N

Thisinvention possesses .nrany other advantages, and has other objectswhich may be made more clearly appap 'ent fromta consideration ofseveral embodiments ofithe invention. For this purpose, there are showna few United States Patent 2,846,016 Patented Aug. 5, 1958 forms in thedrawings accompanying and forming part of the present specification.These forms will now be described in detail, illustrating the generalprinciples of the invention; but it is to be understood that thisdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is an elevation of a fragment of an oil well casing inoperative position in the well hole, and showing a pair of collarsembodying the present invention carried by the casing and cooperatingwith a casing centralizer;

Fig. 2 is an enlarged elevation, showing a collar incorporating thepresent invention and in place upon the well casing;

Fig. 3 is a transverse sectional view, taken along-the plane indicatedby line 33 of Fig. 2;

Fig. 4 is a further enlarged fragmentary sectional view similar to Fig.3, but showing the collar in unclamped position;

Fig. 5 is a sectional view, taken along a plane indicated byline 5-5of'Fig. 4, with some of the parts shown only in phantom lines;

Fig. 6 is a fragmentary broken sectional view, showing the manner inwhich one of the clampingelements of the collar is rotatably. coupled toits supporting member;

Fig. 7 is. a fragmentary pictorial view of an oil well casing, showing acollar of modified form carried by the casing and cooperating with a.casingcentralizer;

Fig. 8 is a fragmentary pictorial view, showingthe connecting elementscarried at the ends of the band;

Figs.- 9, l0 and 11 are plan views, showing the process of constricting.the band about the casing and placing elements atopposite ends of theband in. interlocking relationship by the aid of a collar;

Fig. 12 is a. fragmentary sectional view, taken alon the: planeindicated by line 12-42 of Fig. 11;

Fig. 13 is an enlarged fragmentary sectional view, showing the elementsat opposite ends of the band in engaging relationship;

Fig.: 14 is a view-similar to Fig. 7, but showing another modified formof the present invention;

Fig. 15 is 'a fragmentary sectional view, taken on a plane transverse tothe wall casing and showing'the device of Fig. 14 in operative position;

Fig. 16 is a sectional view, taken along the plane indicatecl'b'y line16-l6 of Fig. 15; r

Fig. 17 is a fragmentary planview of still another modified form ofthe'present invention; and- Fig. 18 is a fragmentary sectional view,taken along the plane indicated by line 1818 of Fig. 17.. 1 r

In the form shown in Figs. 1 to 6, collars 13" are shown that may beused tosupport a structure, such as a casing centralizer, exteriorly ofthe casing. 1

In Fig. 1, there-isshown a section ofa'well. casing'lfl accommodated ina well; bore 11. A' centralizer 12' is slidable within. limits alongtheexterior of .thecasing section 11% v A pair of collarslfi is secured inlongitudinally; spaced relationship along theexterior of thecasing 10'.These collars 13 define the-limits of relative movement; of, thecentralizer 12 I along the casing lfl by appropriate -.cooperation with.end rings 14 of the centralizer 12'.

The collars 13- areof special construction whereby theyrnay be.,afiixedto the casing 10 quite readily v-a nd without performing anywelding operations.

. A flexible tubular member 15, madeofsuitablematerial Such asneopreneor the like, is frictionall-y 'heldin place on the casing 10 bybeing tightl-y constricted-.thera about.

A band 16, made of a thin strip of steel or the like, is accommodatedwithin the tubular member 15. The band 16 has ends 16a and 16b extendingbeyond corresponding opposite ends 15a and 15b of the tubular member 15.The tubular member 15 is generally rectangular in cross-section, havinga through aperture 17 substantially corresponding in shape to the band16 ac commodated therein.

The tubular member 15 is constricted about the casing 10 by firstwrapping the tubular member 15 about the exterior surface of the casing10, and then by drawing the ends of the band 16 toward each other. Thiscompresses that portion of the tubular member 15 that is in contact withthe casing 10. For this purpose and for holding the ends together, aclamp structure is provided. The clamp structure comprises a clampelement 18 and an aperture 19 in which the clamp element engages. Theclamp element 18 is carried by the support 20 secured to one end 16a ofthe band 16. The aperture 19 is located in a support 21 secured to theother end 16b of the band 16. These supports are made of relativelythick metal stock.

The supports 20 and 21 are of arcuate configuration, each having acurvature corresponding substantially to that of the casing 10 withwhich they cooperate. The support 20 is secured on the inner side of theend 16a such that its arcuate contour generally forms a continuation ofthe band 16 when the structure is in operative position on the casing10. Similarly, the support 21 is secured on the inner side of the end1615. Rivets 22 secure the supports to the band ends. The supports '20and 21 limit relative longitudinal movement between the band 16 and thetubular member 15, the ends 20a and 21a of the supports formingshoulders for this purpose.

The combined length of the band 16 and the supports 20 and 21 is suchwith respect to the periphery of the casing 10 that the ends of thesupports 20 and 21 overlap each other. The free end of the support 21 islocated between the casing 10 and the free end of the other support 20.The clamp element 18 and the aperture 19 are located at the overlyingportions of the supports 20 and 21.

The clamp element 18 is mounted for angular movement in the outersupport 20 about an axis 24 (Fig. 3) transverse'to the juxtaposed endsof the supports in a manner to be hereinafter more fully described. Aninwardly extending eccentric projection 23 is integrally formed with theelement 18.

The eccentric projection 23 is received in the clamp aperture 19, andterminates within the confines of the aperture when the parts are inoperative position. In order to install the clamp, the ends of thesupports 20 and 21 are overlapped and the projection 23 inserted intothe aperture 19, with the projection 23 nearest the end of the support20.

The resilience of the band 16 maintains the outwardmost end wall 19a ofthe aperture 19 in engagement with the projection 23.

The projection 23 moves from one side of the axis 24 to the other uponrotation of the element 18. Since the end wall 19a of the aperture 19follows the position of the projection 23, the degree of overlapping ofthe supports 20 and 21 is increased when'the projection is positionedinwardly from the end of the support 20 to cause constriction of theband 16.

In the position of the clamp element 18 shown in Figs. 2 and 3, thesupports 20 and 21 are substantially at their maximum overlappedposition in which the tubular member 16 is tightly constricted about thecasing 10.

When the clamp element 18 is moved to the opposite angular positionabout the axis 24 (Figs. 4 and the supports 20 and 21 are in theirminimum overlapped '4' position. The tubular member 15 is substantiallyupon the casing 10.

The clamping projection 23 is generally rectangular in configuration,with its edges rounded to facilitate its sliding about the walls of theaperture 19 as the element 18 is rotated. As shown in Fig. 5, the lengthof the rectangular projection 23 extends perpendicularly to line 40radial to the axis 24 of rotation of the clamp element 18.

In the position shown in Figs. 4 and 5, the inner side surface 31 of theprojection engages the end wall 19a of the aperture 19. Upon angularrotation of the clamping element 18 in a clockwise direction as viewedin Fig. 5, the upper end 32 of the projection 23 will engage and slidealong the upper right-hand rounded corner 1% of the clamp aperture 19.The opposite or loose lower end 33 of the projection 23 moves generallyarmately away from the wall 19a.

At an intermediate position corresponding to a rotation of the element18 from the position shown in Fig. 5, the projection 23 extendstransversely across and near the top of the aperture 19. Thereafter, theend 32 slides downwardly along the end surface 19:: of the aperture 19,and the other end 33 passes about the rounded upper left-hand corner 19cand then about the upper right-hand rounded corner 19b of the aperture19.

Finally, the projection 23 arrives at a position opposite that shown inFig. 5, and corresponding to Figs. 2 and 3. In this position the outerside surface 34 of the projection engages the end 19a of the aperture19. I

In the clamping position shown in Figs. 2 and 3, the band 16 has passedslightly beyond a condition of maximum stress only slightly exceedingthe stress in the band 16 when the parts are in the clamping positionshown. Maximum stress in the band 16 occurs when the clockwisemost end32 of the projection 23 is inwardmost along the length of the outersupport 20 immediately before arrival of the parts to clamping position.Stability is thus achieved by virtue of the resistance of the tubularmember 15 to increased compression and the resistance of the band 16 toincreased strain.

The clampelements 18 can be operated between clamping and unclampingposition by movement. The aperture 19 is of such size and so located asto permit movement only about one 180 path, such as in a clockwisedirection as viewed in Fig. 5. For this purpose, the aperture 19 is solocated that it extends further above the line 24 than below it; and theaperture is long enough to permit rotation of clamp projection 23 in aclockwise direction through 180. The length of the aperture 19 below theline 24 precludes full 180 arcuate movement of the projection 23thereabout in a counterclockwise direction as viewed in Fig. 5. Byvirtue of this asymmetry, the support 21 has a cross sectional area in aplane passing through the aperture 19 for sustaining the stress in theparts. Low unit stress is thus achieved without increasing the width orthickness of the support 21.

The gripping member 15 is constricted by the metal band 16 so that itsinner periphery is tightly held against the periphery of casing 10. Acircumferential tensile stress is efiective on the band 16 to maintainthe constricted gripping member 15 securely in place upon the casing 10.The band 16 being made from a continuous strip of sheet metal, serves todistribute the constricting force over the area of the member 15 whichis in contact with casing 10.

When the parts are in clamping relationship as shown in Figs. 2 and 3,the end 32 of the projection 23 is opposed to the lower side surface 19dof the aperture 19. This surface 19d forms a relatively sharp cornerwith the operative surface 19a. Interaction of the end 32 with this sidesurface 19d at the corner resists further movement in a clockwisedirection of the clamp element 18. This resistance apprises the operatorthat a stable clamping position has been reached. Furthermore, shouldthe op erator desire to loosen the collar about thev casing 10, thisresistance apprises him that rotation of the element 18 is.in the wrongdirection. Accordingly unclamping movement of the element 18 is properlyaccomplished by counterclockwise rotation of the element 18, as viewedin Figs. 2 and 3.

To ensure against uncoupling movement of the clamping element 18 fromaperture 19 when in clamping position, a guiding plate 35 is provided.This guiding plate 35 is secured between the inner support 21 and theend 16b of the band 16. The plate 35 has a free end spaced outwardly ofthe support 21 in an amount suflicient to accommodate the terminalportion 200 of the outer support 20; When the clamping element 18 ismoved to operative position, the terminal portion 20a of the outersupport 20 enters into the space defined by the plate 35 and the innersupport 21.

The plate 35 clears the terminal portion 20:: of the outer support 20when the parts are in the unclamping position shown in Fig. 4, to permitdesired coupling of the supports 20 and 21. Y

The terminal portion 20a of the support 20 has a beveled edge thatensures appropriate entrance of the end of the outer support 20 betweenthe plate 35 and the inner support 21 upon movement of the parts toclamping position.

The free end of the plate 35 has a semi-circular recess 37 (Figs. 2 and4) conforming to the circular rotatable clamping element 18.

The construction of the clamp element 18facilitating rotative placementupon the support 20 is best shown in Figs. 4 and 6. The clamp element18' has a generally annular periphery, bounded at one end by aperipheral flange 25. The element 18 is guidingly accommodated in athrough annular aperture 26 of the support 20. The flange 25 engages ashoulder 27 formed by an enlarged portion of the recess 26 at the innerside thereof. The interaction of the flange 25 and the shoulder 27limitsoutward movement of the element 18 from the. position shown in Fig. 4.

In order to limit inward movement of the element 18, a stop washer 28 isprovided. This stop washer 28 is accommodated in an annular peripheralrecess 29 ofthe element 18 accessible on the outside of the support 2.0.Inward movement of the element 18 is limited by engagement of the stopwasher 28 with the edges about. the support aperture 26.

For assembling the parts, the stop washer 28may be made of conical formas shown in Fig. 6, and pressed over the end of the element 18 and intoalignment with the groove 29 thereof. The conical stop washer 28 when soin alignment with the groove 29 is flattened by a simple operation. Suchflattening is accompanied by aslight radial restriction whichappropriately locates theinner portion of the washer inwardly of thegroove 29.

A non-circular socket 30, extending axially of the element 18, mayaccommodate a suitable tool or wrench for appropriate rotation of theclamp element 18.

The collar can be placed upon the casing in a short space of timeproperly to locate the casing centralizer 12 or any other structureintended to be carried to the well casing 10.

In the form shown in Figs. 7 through 12, a collar 40 is shown that maybe. used in a manner similar to the collar 13 shown in the previousforms.

A band 41, made of thin strip material such as steel or the like, isaccommodated within a tubular member 42, opposite ends 41a and 41b ofthe band projecting beyond the ends of the tubular member 42.

The band 41 is held in place about the casing 10 by the aid ofinterengaging locking elements integrally formed at the ends 41a and 41bof the band 41. These elements of the band 41 may be brought togetherfor engagement only by constricting the band 41 about the casing. Whenoperative, the locking elements hold the band 41 in constrictedcondition for'firm frictional gagement of the. collar with the casing10.

The locking, elements for the ends 4112 and 41a are formed by outwardlyand inwardly bent ends- 43 and 45 respectively.

The bent ends 43 and 45 extend transversely of the band 41 respectivelyoutwardly and inwardly of the casing' 10. Inner operative surfaces 44and. 46 of the ends 43 and 45 interengage each other to prevent relativeseparation between theends 41a and 41!). A tongue 47, formed centrallyat the terminal portion of the bent end 43 of the band end 41b, entersan aperture 48 provided near the base of the bent end 45 of the otherband end 41a. Interengagement of the tongue 47 and the aperture 48prevents relative sidewise movement between the band ends 41a and 41bwhen in. interlocked relationship.

The locking elements 43 and 45 are brought into operative relationshipby first moving the inwardly extends ing bent end 45 over the outwardlyextending bent end .43 of the respective bent ends 4101 and 41b, andthen moving the bent ends 43 and 45 toward each other. Such relativemovement of the ends 41a and 41b is accomplished by atool 49 shown inFigs. 9, 10 and 11.

The tool 49 comprises a lever arm 50, the end of 'which is adapted toengage the band end 41b. A link arm 51, pivotally mounted on the leverarm 50, is adapted to engage the other band end 41a.

The end of the arm 50 hasa recess or slot 52 in which may be 'seated'the edge at the end of an elongate aperture 53 formed in the band end41b. The end of the link arm 51 has a hook end '57 in whichv may beseated the edge at the end of an aperture 54 formed in the other bandend 41a. The seatsformed in the lever arm 58 and the link arm 51 opposeeach other.v

A pin '55,, carried by the link arm 51,v passesthrough a slot 56 formedin the lever arm50' and serves as'a pivot for the arm 51.

In Fig. 9, the band 41 has been placed about the. casing 10, the lockingelements43 and 45' being spaced from each other since the band isunstressed. The tool 49 is placed in operative position by causing thehook 57 of the link arm 51 to engage in the slot 54 and the notch orslot 52 of the lever arm 50 to engage in the recess 53.

Whenthe tool 49 is initially placedin cooperative relationship with theband ends 4111 and 41b,- the lever arm 50 cooperating with the band end41b is inclined substantially to a line 58 extending radially of thecasing 10 and passing through the seat-forming notch 52.

Upon angular movement of the lever 50 in a direction corresponding tothe arrow 60, the pin 55 is movable in an arcuate path 59 centered aboutthe seat 52.

The path of movement of the pin'55 is suchas to move the link arm 51slightly outwardly of the casing as it is pulled to the right by thelevera'rm 50. The link arm 51, acting through its hook end 57,correspondingly moves the band end 41a.

In the position of the parts shown in Fig. 10, the lever 50 has beenmoved angularly in an amount suflicient to cause the locking element 45to overlie the locking element 43. The slot 56 mounting the pin 55 is solocated on the lever 50 that it extends in a direction normal to a 'linejoining the pin 55 and the seat formed by the hook end 57 when the partsarrive at the position shown in Fig. 10. Accordingly, upon a slightfurther movement of the arm 50, the force produced by the stress in theband 41 acting through the link arm on the pin 55 causes the pin 55 toslide to the opposite end of the slot 56, thereby moving the link 51 andthe end 41a inwardly of thec-asing 10.

In the position shown in Fig. 11, the pin 55 slides to the opposite endof the slot 56, and causes corresponding movement of the link 51 so thatthe locking elements 43 and 45 relatively move into engagement. Thelocking elements 43 and 45 supplant the tool 49 in providing forces formaintaining the band 41 in constricted condition, and the tool 49 can beremoved from the band simply by reverse angular movement of the lever50.

In the assembled position of the band 41 shown in Fig. 11, the band end411), on which is formed the outwardly extending locking element 43,rests against the wall of the casing 10. To permit access of the lowerend of the lever 50 beneath the band end 41b and to permit removalthereof after the band is in assembled relationship, the band end 41b isbowed slightly outwardly. A space 61 is thereby provided in which thelever arm end may be freely accommodated.

As shown in Fig. 12, the operative end of the link arm 51 is offset sothat the reactions at the respective seats formed by the tool 49 arealigned, avoiding an undesired turning couple on the tool.

In the form shown in Figs. l4, l and 16, a band 62 is shown that isstructurally similar to the band 41 shown in the previous form. In thisinstance, however, the band 62 forms an integral part of a scraperstructure intended to be positioned on the casing 10. A series ofscraper elements 63 is secured in place upon the band 62. Each scraperelement 63 is generally of wire or rod-like con figuration, projectingradially outwardly through a transverse aperture 64 in the band 62 (Fig.16). An integrally formed head 65 on each scraper element 63 abuts theedges about the band aperture 64 on the inner side of the band properlyto orient the scraper element 63.

A resilient member 66, generally similar to the member 15, is providedfor ensuring proper frictional engagement of the scraper with the casing10. Opposite lateral edges of the band 62 are accommodated in recesses67 located on the inner sides of outwardly extending flanges 68 of theresilient member 66. The outer surface of the hand 62 is thus exposed.

In Fig. 15, the band 62 is placed in operative position by the .tool 49.The tool 49 operates in the same manner as in the previous form. Theband 62 has locking elements 69 and 70, as in the previous form.Recesses 71 and 72 near the ends of the band 62 cooperate with the tool49 for constricting the band 62 about the casing 10.

In the form shown in Figs. 17 and 18, theends 80a and 80b of a metalband 80 are held together in a slightly different manner. The band ends80a and 80b have integrally formed rounded ends 82 and 83 forming eyescapable of being aligned to receive a cotter pin 81. The eyes 82 and 83are brought into alignment by the tool 49, as shown in Fig. 18.

By virtue of the structures being capable of attachment to the casingwithout a Welding operation, the desirable metallurgical properties ofthe casing 10 are retained.

The inventor claims:

1. In a stop collar adapted to be mounted on a well casing: a split bandadapted to be disposed about the exterior of the well casing; a pliantelastic gripping memher extending at least within the band and adaptedto be compressed in gripping engagement with the casing uponconstriction of the hand; the end portions of the band on opposite sidesof its split providing projections extending in opposite lateraldirections and adapted to be placed in overlapping engagement with eachother to prevent circumferential separation between the band ends and tomaintain the gripping member in gripping engagement with the casing;said band having apertures in its end portions adapted to receive ameans for shifting said end portions toward each other to grip thegripping member with the casing and to place said projections inoverlapping engagement with each other.

2. In a stop collar adapted to be mounted on a well casing: a split handadapted to be disposed about the exterior of the well casing; 21 pliantelastic gripping member extending at least within the band and adaptedto be compressed in gripping engagement with the casing uponconstriction of the band; the end portions of the band on opposite sidesof its split providing projections extending in opposite lateraldirections and adapted to be placed in overlapping engagement with eachother to prevent circumferential separation between the band ends and tomaintain the gripping member in gripping engagement with the casing;said band having apertures in its end portions adapted to receive ameans for shifting said end portions toward each other to grip thegripping member with the casing and to place said projections inoverlapping engagement with each other; one of said end portions havinga terminal opening adjacent its projection; and a tongue on the terminalportion of the projection of the other end portion disposed in saidopening to prevent relative axial movement between said end portions. l

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Sams Oct. 18, 1955

